<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <script src="jquery-3.1.1.js"></script>
    <style>
    span{
        margin: 0;
        padding: 0;
        display: block;
        width: 100px;
        height: 30px;
        /*border: 1px solid black;*/
        float: left;
        text-align: center;
        color: white
    }
    span:hover{
        background-color: gray;
        color: black;
    }
    header{
        margin: 0;
        padding: 0;
        width: 500px;
        height: 30px;
        background-color: black;
    }
    main{
        width: 500px;
    }
    li{
        display: block;
        width: 100px;
        height: 30px;
        /*border: 1px solid black;*/
        text-align: center;
        display: none;
        
    }
    div{
        margin: 0;
        padding: 0;
        width: 100px;
        /*height: 200px;*/
        /*border: 1px solid black;*/
        position: absolute;
        left: 200px;
        
    }
    main{
        margin: 0;
        padding: 0;
        width: 500px;
        /*height: 500px;*/
        /*border: 1px solid black;*/
    }
    .l4{
        display: block;
        width: 100px;
        height: 30px;
        /*border: 1px solid black;*/
        text-align: center;
        /*display: none;*/
    }
    .u1{
        display: block;
        margin: 0;
        padding: 0;
        position: relative;
        left: 200px;
        /*top: -5px;*/
        /*display: none;*/

    }
    .u2{
        display: block;
        margin: 0;
        padding: 0;
        position: relative;
        left: 200px;
        /*top: -65px;*/
        /*display: none;*/
    }
    .u3{
        display: block;
        margin: 0;
        padding: 0;
        position: relative;
        left: 200px;
        /*top: -160px;*/
        /*display: none;*/
    }
    </style>
</head>
<body>
    <header>
    <span class="s1">选项一</span>
    <span class="s2">选项二</span>
    <span class="s3">选项三</span>
    <div style="clear: both"></div>
    </header>
    <!--<div class="d1"></div>-->
    <main>
    <ul class="u1">
        <li>内容1</li>
        <li>内容1</li>
    </ul>
    <ul class="u2">
        <li>内容2</li>
        <li>内容2</li>
        <li>内容2</li>
    </ul>
    <ul class="u3">
        <li>内容3</li>
        <li>内容3</li>
        <li>内容3</li>
        <li>内容3</li>
    </ul>
    </main>
</body>
</html>
<script>
    $('.s1').mouseover(function(){
        
        $('.u1>li').addClass('l4')
        $('.u2>li').removeClass('l4');
        $('.u3>li').removeClass('l4');
        $('main').css('border','1px solid black')
    })
     $('.s2').mouseover(function(){
        
        $('.u2>li').addClass('l4')
        $('.u1>li').removeClass('l4');
        $('.u3>li').removeClass('l4');
        $('main').css('border','1px solid black')
    })

     $('.s3').mouseover(function(){
        
        $('.u3>li').addClass('l4')
        $('.u2>li').removeClass('l4');
        $('.u1>li').removeClass('l4');
        $('main').css('border','1px solid black')
    })














</script>